DESCRIPTION: This mentored research scientist development award (KU 1) requests support for Dr. Inna Dardynskala, Research Associate Professor in Environmental and Occupational Health Sciences under the mentorship of Dr. Daniel Hryhorczuk, Professor of Environmental and Occupational Health Sciences and Epidemiology at the University of Illinois School of Public Health. The applicant will supplement the mentorship experience with coursework in occupational health and epidemiology. Portions of the research will be supported by our Fogarty grant for "International Research and Training in Environmental and Occupational Health." The goal of Dr. Dardynskaia?s research study is to assess whether a cohort of chemical workers exposed to chlorinated phenols, chiorphenoxy acids, and their chlorinated dioxin and dibenzofuran contaminants at the Khimprom chemical plant in Ufa, Bashkortostan experienced adverse reproductive outcomes as a result of these exposures. Despite a large body of experimental data on the adverse reproductive effects of CDDs and CDFs in animals, -the human data are still sparse. While lowered sex ratio appears to be a reproductive outcome among groups with heavy occupational or environmental exposure to these compounds, this association is far from proven. The Ufa cohort gives us a rare opportunity to study this association in one of the most heavily dioxin-exposed occupational cohorts in the world. Given the ubiquity of environmental exposure to these compounds and their ability to disrupt endocrine systems at low doses, the question of whether they can affect reproductive outcomes in humans is indeed significant. The Ufa cohort consists of approximately 500 individuals employed in the production of chlorphenoxy herbicides at this plant between 1961 and 1987. The reproductive experience of this cohort will be compared to that of an unexposed cohort of nearest neighbor controls, matched to the exposed on gender and age. Exposure will b about ascertained through plant employee records, the plant chloracne registry, and an occupational and environmental history questionnaire. Reproductive outcomes will be assessed through administration of a reproductive history questionnaire to female workers and controls and to male workers and their spouses/partners, through medical abstraction of delivery records of offspring, and through review of birth certificate data.